#include <bits/stdc++.h>
#ifndef DEBUG
#define debug
#endif
using namespace std;
using i64 = int64_t;

const int inf = LLONG_MIN / 2;
int main() {
  cin.tie(0)->sync_with_stdio(0);
  int n, x0;
  cin >> n >> x0;
  struct Node { int x, y, v; };
  vector<Node> node(n + 1);
  for (int i = 1; i <= n; i ++) cin >> node[i].x;
  for (int i = 1; i <= n; i ++) cin >> node[i].y;
  for (int i = 1; i <= n; i ++) cin >> node[i].v;
  sort(node.begin() + 1, node.end(), [](Node &a, Node &b) {
    return a.x < b.x;
  });
  int totaly = 0;
  vector<int> sumv(n + 1);
  for (int i = 1; i <= n; i ++) {
    totaly += node[i].y;
    sumv[i] = sumv[i - 1] + node[i].v;
  }

  vector<vector<array<i64, 2>>> dp(n + 1, vector<array<i64, 2>>(n + 1, {inf, inf}));
  for (int l = n; l >= 1; l --) {
    dp[l][l][0] = dp[l][l][1] = totaly - (i64)abs(x0 - node[l].x) * sumv[n];
    for (int r = l + 1; r <= n; r ++) {
      int totalv = sumv[n] - sumv[r] + sumv[l];
      dp[l][r][0] = max(
        dp[l + 1][r][0] - (i64)abs(node[l + 1].x - node[l].x) * totalv,
        dp[l + 1][r][1] - (i64)abs(node[r].x - node[l].x) * totalv
      );
      totalv = sumv[n] - sumv[r - 1] + sumv[l - 1];
      dp[l][r][1] = max(
        dp[l][r - 1][0] - (i64)abs(node[r].x - node[l].x) * totalv,
        dp[l][r - 1][1] - (i64)abs(node[r].x - node[r - 1].x) * totalv
      );
    }
  }
  cout << fixed << setprecision(3);
  cout << max(dp[1][n][0], dp[1][n][1]) / 1000.0 << endl;
}